Apparatus for producing carbon black

ABSTRACT

A carbon black reactor is characterized by a converging zone, a throat, a first reaction zone and a second reaction zone serially connected. Oil can be injected both upstream and downstream of the throat. Annular walls connect the throat with the first reaction zone and the first reaction zone with the second reaction zone.

This application is a division of application Ser. No. 759,376, filedJuly 26, 1985, now pending.

BACKGROUND OF THE INVENTION

In one aspect, the invention relates to a process for producing carbonblack. In another aspect, the invention relates to an apparatus forproducing carbon black.

"Hard" or tread type carbon blacks having a surface area in the range offrom about 70 to about 125 m² /g as measured by the CTAB method areusually produced by using a different process and reactor than that usedfor the production of "soft" or carcass type carbon black having a CTABsurface area in the range of about 25 to about 70 m² /g. The necessityof having different reactors for different products is burdensome forcarbon black plants and the desirability of a single reactor which couldproduce both types of blacks is manifest. Also, it has been noted thatthe yield of "soft" carbon blacks on the basis of oil feedstock used isgenerally lower than theoretical yield. A soft black reactor thatprovides higher yield or efficiency could provide cheaper product, andwould thus be very desirable.

Grit is another problem in carbon black production. High grit levels inthe carbon black product sometimes requires the purchase ofmicropulverizers as plant equipment. Grit is believed by some to have anadverse impact on compounding carbon black into rubber as well aseroding compounding equipment. Clearly a reactor and process thatprovide low grit levels in the carbon black product would be desirable.

A reactor which operates in a stable manner is clearly very desirable.The various process inputs must be changed when it is desired to switchover to a new product and the ability to duplicate earlier runs canprovide substantial savings in manpower and reduce production ofoff-specification product.

OBJECTS OF THE INVENTION

It is the first object of this invention to provide a carbon blackreactor that can produce both hard blacks and soft blacks.

It is another object of this invention to provide a carbon black reactorand process that provide high yields of carbon black product.

It is a further object of this invention to provide a reactor andprocess which operates in a stable manner and provides low grit levelsin the final product.

SUMMARY OF THE INVENTION

In one embodiment of the invention, a carbon black reactor comprises arefractory sidewall which defines a reaction flow passage having alongitudinal axis. A combustion zone and a reactor throat are positionedalong the longitudinal axis of the reactor and a converging zoneconverges from the combustion zone to the reactor throat. A quench zoneis spaced apart from the reactor throat and has a cross sectionaldimension of at least three times the cross sectional dimension of thereactor throat and a reaction zone connects the reactor throat with thequench zone. The reaction zone has a cross sectional dimension less thanthat of the quench zone and in the range of 1.2 to 3 throat diameters.The reaction zone has a length in the range of from 2 to 6 throatdiameters. A first annular and or near annular wall connects the reactorthroat with the reaction zone. A second annular or near annular wallconnects the reaction zone with the quench zone. A burner is operablyassociated with the combustion zone to cause axial flow of hotcombustion gases from the combustion zone to the quench zone. At leastone port for receiving an oil injector for introducing a carbonaceousfeedstock radially inwardly toward the longitudinal axis of the reactionflow passage is provided through the side wall of the converging zone.Another at least one port for receiving an oil injector for introducinga carbonaceous feedstock generally radially inwardly toward thelongitudinal axis of the reaction flow passage is provided through theside wall of the reaction zone. The reactor is further provided with ameans for introducing quench fluid into the quench zone. By providingoil injectors in the ports on both sides of the reactor throat, carbonblack can be produced at unexpectedly high efficiencies, especially softcarbon blacks, although both hard carbon blacks and soft carbon blackscan be produced by positioning injectors in either the converging orreaction zones. The annular or near annular walls separating the throatfrom the reaction zone and the reaction zone from the quench zoneprovide stable combustion and, provided that the ratio between thediameter of the quench zone and the reaction zone is sufficiently large,provides low levels of grit and minimal problems with carbon depositionson the inside of the reactor wall. By providing ports both upstream anddownstream of the throat, the reactor is easily set up to produce hardor soft blacks, as desired. The reactor is capable of producing both harand soft blacks at good efficiency.

In another aspect of the invention, a process is provided for producingcarbon black. A hydrocarbon fuel is combusted with an excess amount ofoxygen-containing gas to form a mass of hot combustion gases. These hotcombustion gases are flowed through a converging zone and a carbonaceousfeedstock is introduced generally radially inwardly into the hotcombustion gases from the periphery of the converging zone to form afirst reaction mixture. The first reaction mixtures flows through areactor throat, past an abrupt expansion zone in the reaction flowpassage at the downstream end of the throat and into the upstream end ofa reaction zone. In the reaction zone, additional carbonaceous feedstockis introduced generally radially inwardly from the periphery of thereaction zone to form a second reaction mixture and the second reactionmixture is flowed past an abrupt expansion in the reaction flow passageat the downstream end of the reaction zone and into a quench zone whichhas a sufficiently large diameter and length to provide for theformation of the carbon black. The process can be carried out in theabove described reactor if desired to produce both hard and soft blacksas desired with low levels of grit and high efficiencies.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a cross-sectional view of a carbon black reactorembodying certain features of the present invention.

FIG. 2 is a cross-sectional view of the reactor in FIG. 1 along lines2--2 of FIGURE l.

DETAILED DESCRIPTION OF THE INVENTION

A carbon black reactor 2 comprises a refractory sidewall 4 for defininga reaction flow passage 6 having a plurality of zones positioned along alongitudinal axis 8. The sidewall 4 determines a combustion zone 10 anda reactor throat 12. A converging zone 14 converges from the combustionzone 10 to the reactor throat 12. A quench zone 16 is provided which hasa cross sectional dimension of at least three times the cross sectionaldimension of the reactor throat 12. A reaction zone 18 connects thereactor throat 12 with the quench zone 16. The reaction zone 18 has across sectional dimension less than that of the quench zone 16 and inthe range of from about 1.2 to 3 throat diameters. The length of thereaction zone 18 is in the range of from 1 to 6 throat diameters. Afirst annular or near annular wall 20 connects the reactor throat 12with the reaction zone 18. A second annular or near annular wall 22connects the reaction zone 18 with the quench zone 16. A burner 24 ispositioned for axial flow of combustion gases from the combustion zone10 to the quench zone 16. At least one port for an oil injector 26 isprovided for introducing a carbonaceous feedstock generally radiallyinwardly toward the longitudinal axis 8 of the reaction flow passage 6from the side wall of the converging zone 14. At least one port for anoil injector 28 is provided for introducing carbonaceous feedstockgenerally radially inwardly toward the longitudinal axis 8 of thereaction flow passage from the sidewall of the reaction zone 18. Thereactor further comprises a means 30 for introducing a quench fluid intothe quench zone. If desired, oxygen-containing gases can be introducedtangentially or radially into the reaction flow passage 6 via one ormore of the following: at least one tunnel 32 positioned at the upstreamend of the combustion zone 10; at least one tunnel 34 positioned at theupstream end of the reaction zone 18; and/or via at least one tunnel 36at the upstream end of the quench zone 16. Secondary air can also beintroduced into the quench zone 16 if desired in a radial or tangentialmanner. For example, a radial tunnel 38 is shown emptying into thequench zone 16.

In a preferred embodiment, the combustion zone 10 has a generallycylindrical shape and a length in the range of from 2 to 5 reactorthroat diameters. The conversion zone 14 has a frustoconical shape and alength in the range of from 2 to 5 throat diameters. The reactor throat2 has a length in the range of from 0.2 to 2 reactor throat diameters,preferably 0.2-0.7 throat diameters. Preferably, at least two oilinjectors 26 are positioned longitudinally spaced apart in theconverging zone 14 and at least one oil injector is positioned in thereaction zone 18 through parts in the refractory material. Each of theoil injectors 26 is preferably radially inwardly directed. The oilinjectors 26 in the converging zone are preferably located at a firstlongituinal position with respect to the reaction flow passage 6 and asecond longitudinal position with respect to the reactor flow passage 6.The at least one generally radially inwardly directed oil injector 28 inthe reaction zone 18 is positioned at a third longitudinal position withrespect to the reactor axis 8.

The reaction zone 18 usually has a diameter in the range of from about1.3 to about 2.7 times the diameter of the reactor throat. The reactionzone 18 will usually have a length sufficiently short so that thereacting mass is emitted from it before carbon forming reaction iscomplete. For example, a preferable length for the reaction zone 18 isin the range of from 2 to 5 reactor throat diameters. Preferably, thefirst wall 20 which connects there action zone 18 with the reactorthroat 12 is annularly shaped. The wall 22 is also annularly shaped. Theannularly shaped walls provide advantage by assisting in thedisassocation of the oil particles for efficient pyrolysis. In acommercial size reactor, the diameter of the reactor throat 12 willusually be in the range of from 5 to 10 inches.

The burner 24 is axially directed into the combustion zone 10 from anupstream end thereof in a preferred embodiment of the invention. In thismanner, hot combustion gases can be caused to flow axially from thecombustion zone to the quench zone. One suitable burner can be formed bypositioning a gas tube 40 in a tunnel 42 at the upstream end of thecombustion zone 10. Fuel such as natural gas from a source 44 is emittedfrom the tube 40 via apertures 41 and is combusted with air from airsources 46. Good air distribution in the tunnel 42 is provided bycausing the air from opposed tunnels 50 to flow in an annulus in theupstream direction and around lip 52 of a tubular gas distributor 54.

In another aspect, the invention provides a process for producing carbonblack in a reaction flow passage 6. A hydrocarbon fuel such as fromsource 44 is combusted with excess amounts of oxygen containing gas,such as air, from source 46 to form a mass of hot combustion gases.These hot combustion gases are flowed through a converging zone such aszone 14. A carbonaceous feedstock is introduced generally radiallyinwardly into the hot combustion gases from the periphery of theconverging zone 14 to form a first reaction mixture. The first reactionmixture flows through the reactor throat 12, past an abrupt upstreamexpansion in the reaction flow passage 6 at the downstream end of thethroat 12 and into the upstream end of a reaction zone 18. In thereaction zone 18 additional carbonaceous feedstock is introducedgenerally radially inwardly into the reaction mixture from the peripheryof the reaction zone 18 to form a second reaction mixture and thissecond reaction mixture flows past the second expansion in the reactionflow passage 6 and into a quench zone 16. The quench zone 16 has asufficiently large diameter and a length to provide for the formation ofcarbon black from the resulting pyrolysis of the second reactionmixture.

The required inputs of oxygen-containing gas, which is usually air;fuel, which preferably natural gas although oil can be used, andcarbonaceous feedstock, such as a residual oil having a high carboncontent as measured; for example, by BMCI, depends on the size of thereactor throat 12. Where R is the radius of the reactor throat ininches, the combustion gas flow rate is usually in the range of fromabout 9,000 R² to 25,000 R², preferably in the range 11,000 R² -19,000R², the combustion gas flow rate being expressed in terms of standardcubic feet per hour (SCFH) at 1 atmosphere and 60° F. Hard blacks arebetter produced at the higher flow rates in the range. The charge rateof the carbonaceous feedstock is dependent upon the type of carbon blackdesired, the air/fuel ratio, the oil BMCI value, etc. but will generallybe most closely related to the air rate. The oil rate will usuallyprovide an air/oil ratio in the range of 250:1 to 750:1 SCF/Gal. Atleast when producing low surface area blacks, such as blacks having asurface area in the range of 25 to 70 m² /g, it is advantageous toinject the oil on both sides of the reactor throat 12. For example,improved yield will result when the reactor is operated at an air/oilratio in the range of 250:1 to 500:1 SCF/Gal. and feedstock injection isin both the converging and reaction zones. The most upstream position ofcarbonaceous feedstock injection will generally be separated from themost downstream position by distance in the range of from 2 to about 7throat diameters. Preferably, the distance separating the most upstreamfrom the most downstream position of carbonaceous feedstock injectionwill be in the range of from 3 to 6 reactor throat diameters so that theoil from the downstream injector contacts reactive particles from theupstream injector(s). Based on the examples herein, it appears that bestresults are obtained with combusting the fuel with from 100 to 150%, forexample, about 120%, of the amount of oxygen-containing gas required forstoichiometric combustion.

It is generally desirable to scavenge heat from the process wherepossible. One manner in which this can be done is to preheat the aircharged to the reactor. By indirectly exchanging heat with reactor tailgas, the air charge becomes preheated, frequently to a temperaturewithin the range of 500° to 800° C.

Experiments have shown that providing the oil injectors with spray tipsso that a cone-shaped spray of feedstock is emitted from each productsblack at higher efficiency that where coherent jets of feed are usedalthough the present invention is not limited to sprays or jets offeedstock. For best results, it is recommended that oil injector eachemit a cone-shaped spray of feedstock. A wide cone angle is preferred,such as a cone angle in the range of from 60° to 120°.

The quench fluid is usually supplied to the quench zone in an amountsufficient to reduce the temperature of the reactor gases to below about1800° F. and terminate the carbon forming reaction. In a commercialunit, the quench fluid will be introduced at a distance in the range offrom about 10 to about 30 throat diameters from the outlet of thereactor throat. By providing a plurality of longitudinally spaced portsfor the positioning of the quench injector at a desired location thephotolometer of the carbon black product can be controlled. It isimportant that the quench zone 16 not be so large that liquid waterbegins to accumulate therein because of low gas velocities. There isthus a practical upper limit to the diameter of the quench zone 18 whichcan be varied to some extent by the use of bifluid nozzles for theintroduction of quench fluid for example.

In a preferred embodiment of the invention the reaction zone has adiameter in the range of from 1.1 to 3.0 throat diameters and the quenchzone has a diameter in the range of from 3 to 10 reactor throatdiameters. In a reactor which was tested with good results, the reactionzone had a diameter of about 1.8 times the throat diameter and thequench zone had a diameter of about 6.7 times the throat diameter. Thelower limit to the diameter of the quench zone is set by the occurrenceof carbon deposits. In a reactor that was tested in which the quenchzone had a diameter of 2.8 times the throat diameter carbon depositswere a severe problem. After quenching, the reactor effluent can bewithdrawn via tail pipe 62 and processed in conventional equipment.

Example

Runs were made in a pilot plant sized apparatus similar to that shown inFIGS. 1 and 2. The reactor throat had a diameter of 1.7 inches. Thereaction zone had a diameter of 3 inches. The quench zone had a diameterof 12 inches. The throat was 1 inch long. The reaction zone was 6 incheslong. An axial quench nozzle was positioned about 15 feed downstreamfrom the throat outlet. Radial oil injection was selected from positions4 inches upstream from the throat outlet (4), 2 inches upstream fromthroat outlet (2), and 41/2 inches downstream from throat outlet (-5).The oil was emitted through orifices ranging from 0.028" to 0.046" asshown. Provision was made for supplying tangential air to the upstreamend of the reaction zone and radial secondary air 76 inches downstreamfrom throat outlet and 108 inches downstream from throat outlet. Atwo-stage converging zone was employed, the upstream stage had anupstream diameter of 6.0" and a length of 2" to a downstream diameter of4.5". The downstream portion had an upstream diameter of 4.5" and alength of 13" to a downstream diameter at the throat of 1.7". Runs madein this reactor are summarized in the following table. An air jacket wasprovided around the gas tube for cooling.

                                      TABLE I                                     __________________________________________________________________________                  Run                                                                           1   2   3   4   5   6   7   8   9                               __________________________________________________________________________    Prim Air,                                                                            SCFH   13790                                                                             13790                                                                             13790                                                                             13790                                                                             13790                                                                             13790                                                                             11820                                                                             9850                                                                              7880                                   °C.                                                                           558 562 560 561 563 561 558 563 563                             Jacket Air,                                                                          SCFH   394 394 394 394 394 394 394 394 394                             Tang Air,                                                                            SCFH   0   0   0   0   0   0   0   0   0                               Sec. Air,                                                                            SCFH   0   0   158 2172                                                                              0   1478                                                                              0   0   0                                      Location                                                                             --  --  68  68  --  108 --  --  --                              Total Air,                                                                           SCFH   14184                                                                             14184                                                                             14342                                                                             16356                                                                             14184                                                                             15662                                                                             12214                                                                             10244                                                                             8274                            Gas Rate,                                                                            SCFH   933 933 933 933 933 933 800 667 533                             Air/Gas Ratio 15.2                                                                              15.2                                                                              15.4                                                                              15.2                                                                              15.2                                                                              15.2                                                                              15.3                                                                              15.4                                                                              15.5                            Oil Rate,                                                                            gph    23.17                                                                             41.28                                                                             41.53                                                                             44.86                                                                             41.39                                                                             43.27                                                                             34.56                                                                             29.04                                                                             23.75                           A/O,   scf/gal                                                                              612 344 342 316 343 328 353 353 348                             Oil Tubes     2-.039                                                                            2-.042                                                                            2-.042                                                                            2-.062                                                                            2-.042                                                                            2-.046                                                                            2-.042                                                                            2-.042                                                                            2-.039                          Location      4   4   4/-5                                                                              4   -5  -5  -5  - 5 -5                              Pressure, psig                                                                              70  131 70-80                                                                             46  130 90  99  68  70                              Temp °C.                                                                             156 163 158 162 162 163 156 154 155                             Yield, lb/gal 4.83                                                                              6.42                                                                              6.37                                                                              6.29                                                                              6.60                                                                              6.39                                                                              6.45                                                                              6.42                                                                              6.42                                   % Total C                                                                            50.1                                                                              71.2                                                                              70.7                                                                              70.3                                                                              73.2                                                                              71.2                                                                              71.3                                                                              71.1                                                                              71.2                            I.sub.2 No (ASTM D 1510 76)                                                                 117 39  44  40  35  37  36  38  37                              CTAB (ASTM D 3765 80)                                                                       113 43  49  44  40  39  42  42  42                              24M4 (ASTM D 3493 76)                                                                       107 93  96  93  89  88  89  90  89                              Grit (ASTM D 1514-80)                                                                       --  --  --  --  .0020                                                                             .0006                                                                             .0004                                                                             .0003                                                                             .0006                           325 sieve, wt %                                                               __________________________________________________________________________                  10  11  12  13  14  15  16  17  18                              __________________________________________________________________________    Prim Air,                                                                            SCFH   13790                                                                             13790                                                                             13790                                                                             13790                                                                             13790                                                                             13790                                                                             13790                                                                             13790                                                                             14381                                  °C.                                                                           560 562 562 562 413 28  564 564 563                             Jacket Air,                                                                          SCFH   394 394 394 394 394 394 394 394 394                             Tang Air,                                                                            SCFH   394 591 0   0   0   0   0   0   0                               Sec. Air,                                                                            SCFH   0   0   0   0   0   0   0   0   0                                      Location                                                                             --  --  --  --  --  --  --  --  --                              Total Air,                                                                           SCFH   14578                                                                             14775                                                                             14184                                                                             14184                                                                             14184                                                                             14184                                                                             14184                                                                             14184                                                                             14775                           Gas Rate,                                                                            SCFH   933 933 933 933 933 933 609 609 933                             Air/Gas Ratio 15.2                                                                              15.2                                                                              15.2                                                                              15.2                                                                              15.2                                                                              15.2                                                                              23.3                                                                              23.3                                                                              15.2                            Oil Rate,                                                                            gph    43.27                                                                             42.99                                                                             43.56                                                                             43.56                                                                             36.84                                                                             26.93                                                                             41.27                                                                             41.97                                                                             42.87                           A/O,   scf/gal                                                                              328 330 326 326 385 527 344 338 345                             Oil Tubes     2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                          Location      -5  -5  -5  -5  -5  -5  4   4   4                               Pressure, psig                                                                              93  93  140 130 107 60  95  97  98                              Temp °C.                                                                             162 163 162 161 162 159 160 160 161                             Yield, lb/gal 6.45                                                                              6.43                                                                              6.57                                                                              6.57                                                                              6.35                                                                              5.67                                                                              5.88                                                                              5.92                                                                              6.34                                   % Total C                                                                            71.8                                                                              71.6                                                                              73.1                                                                              73.2                                                                              69.7                                                                              60.1                                                                              67.2                                                                              67.8                                                                              70.5                            I.sub.2 No    38  35  36  36  38  36  41  39  45                              CTAB          41  41  40  40  41  39  44  42  49                              24M4          87  88  88  88  88  82  87  86  92                              Grit          .0020                                                                             .0004                                                                             .0005                                                                             .0004                                                                             .0002                                                                             .0004                                                                             .0016                                                                             .0010                                                                             .0030                           __________________________________________________________________________                  19  20  21  22  23  24  25  26  27                              __________________________________________________________________________    Prim Air,                                                                            SCFH   7880                                                                              13647                                                                             13645                                                                             13667                                                                             13870                                                                             13849                                                                             13858                                                                             13865                                                                             13862                                  °C.                                                                           565 563 562 561 564 559 561 562 560                             Jacket Air,                                                                          SCFH   394 380 391 391 395 396 396 397 396                             Tang Air,                                                                            SCFH   0   0   0   0   0   0   0   0   0                               Sec. Air,                                                                            SCFH   0   0   0   0   0   0   0   0   0                                      Location                                                                             --  --  --  0   0   0   0   0   0                               Total Air,                                                                           SCFH   8274                                                                              14026                                                                             14035                                                                             14058                                                                             14265                                                                             14246                                                                             14255                                                                             14262                                                                             14258                           Gas Rate,                                                                            SCFH   533 1162                                                                              1161                                                                              1160                                                                              1085                                                                              1058                                                                              1150                                                                              1163                                                                              1163                            Air/Gas Ratio 15.5                                                                              12.1                                                                              12.1                                                                              12.1                                                                              13.1                                                                              13.5                                                                              12.4                                                                              12.3                                                                              12.3                            Oil Rate,                                                                            gph    15.94                                                                             38.32                                                                             38.32                                                                             38.88                                                                             41.30                                                                             41.74                                                                             38.83                                                                             38.32                                                                             32.05                           A/O,   scf/gal                                                                              519 366 366 362 345 341 367 372 445                             Oil Tubes     2-.039                                                                            2-.046                                                                            2-.028/                                                                           2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                                                                            2-.046                                                2-.039                                                  Location      4   -5  2/-5                                                                              -5  -5  -5  4/-5                                                                              4   4/-5                            Pressure, psig                                                                              40  70  50  93  100 110 80  85  50                              Temp °C.                                                                             185 157 160 160 161 162 159 160 156                             Yield, lb/gal 5.32                                                                              6.78                                                                              6.59                                                                              6.77                                                                              6.69                                                                              6.62                                                                              6.54                                                                              6.51                                                                              6.20                                   % Total C                                                                            56.7                                                                              72.8                                                                              70.7                                                                              72.8                                                                              73.1                                                                              72.6                                                                              70.6                                                                              70.0                                                                              65.3                            I.sub.2 No    100.5                                                                             40  52  40  42  38  50  47  71                              CTAB          90  42  54  44  42  42  57  50  72                              24M4          100 89  99  92  90  90  100 91  102                             Grit   non magnetic                                                                         .0010                                                                             .0007                                                                             .0012                                                                             .0004                                                                             .0009                                                                             0   .0005                                                                             .0010                                      total  .0031                                                                             .0066                                                                             .0027                                                                             .0009                                                                             .0015                                                                             0   .0005                                                                             .0015                               __________________________________________________________________________

Injection of oil upstream and downstream of the venturi throat seems togive much higher efficiency as indicated by the higher CTAB value forthe black produced. Compare runs 3 with 2 and 5, and 21 with 20 and 26and 25 with 22 and 26. This shows the unexpected result that splittingthe oil improves soft black reactor efficiency because it produceshigher CTAB at essentially the same input conditions. In fact, th firsttest of oil in both locations was made in a deliberate effort to producea lower CTAB black. This "split oil" mode was also tested when producinga low surface area hard black (run 27). The improvement in efficiencywhen splitting the oil streams is definite at high oil rates and lowsurface areas.

That which is claimed is:
 1. A carbon black reactor comprising(a) arefractory sidewall defining a reaction flow passage having alongitudinal axis, said passage having the following zones:(i) acombustion zone; (ii) a reactor throat zone; (iii) a converging zoneconverging from said combustion zone to said reactor throat zone; (iv) aquench zone having cross sectional dimension of at least three times thecross sectional dimension of said reactor throat zone; (v) a reactionzone connecting said reactor throat zone with said quench zone, saidreaction zone having a cross sectional dimension less than that of saidquench zone and in the range of 1.1 to 3 reactor throat diameters and alength in the range of 2 to 6 reactor throat diameters; and (vi) a tailpipe zone connecting said quench zone with an exit port;said sidewallfurther forming a first generally radially perpendicular wall where saidreactor throat zone connects with said reaction zone; said sidewallfurther forming a second generally radially perpendicular wall wheresaid reaction zone connects with said quench zone; (b) a burnerpositioned for axial flow of combustion gases from said combustion zonethrough said quench zone and out said tail pipe zone; (c) port meansradially extending through said sidewall in said converging zone forpositioning at least one oil injector means and oil injector meansassociated therewith for introducing a carbonaceous feedstock radiallyinwardly toward said longitudinal axis; (d) port means radiallyextending through said sidewall in said reaction zone for positioning atleast one oil injector means and oil injector means associated therewithfor introducing a carbonaceous feedstock generally radially inwardlytoward said longitudinal axis; and (e) port means for introducing aquench fluid into said quench zone.
 2. A carbon black reactor as inclaim 1 wherein said combustion zone has a generally cylindrical shapeand a length in the range of from 2 to 5 reactor throat zone diameters;wherein said converging zone has a frustoconical shape and a length inthe range of from 2 to 5 reactor throat zone diameters, and wherein saidreactor throat zone has a length in the range of from 0.2 to 2 reactorthroat zone diameters and said reaction zone has a plurality of said oilinjector means positioned therein.
 3. A carbon black reactor as in claim2 further having a plurality of said oil injector means positioned insaid converging zone, wherein at least one such oil injector means islocated at a first longitudinal position with respect to saidlongitudinal axis, at least one such oil injector means is located at asecond longitudinal position with respect to said longitudinal axis andwherein at least one such oil injector means is located at a thirdlongitudinal position with respect to said longitudinal axis.
 4. Acarbon black reactor as in claim 3 wherein said reaction zone has adiameter in the range of from about 1.5 to about 2.5 times the diameterof said reactor throat zone and a length in the range of 1 to 5 reactorthroat zone diameters, and said quench zone has a diameter in the rangeof from about 3 to 10 times the diameter of said reactor throat zone. 5.An apparatus as in claim 4 wherein said first wall is generallyannularly shaped;wherein said second wall is generally annularly shaped;wherein the diameter of the said reactor throat zone is in the range offrom 5 to 10 inches; and wherein said burner is axially directed intosaid combustion zone from an upstream end thereof to cause combustiongases to flow from said combustion zone to said quench zone.